You're correct about which weapon to use. I purchased the AR and S&W because I fired an M-16 and a .45 before. After I had them for about a week I then knew it was a dumb move because of just what you said. "High powered pistol and rifle rounds can easily go through walls and strike friendlies." Should have thought a little more about what to purchase before I made the investment. We had a few break ins in our community and decided I should not sit back - I should buy something quickly.I came out of law school with only two pieces of practical information. One was from my criminal law professor. He told us the law permits a person to use force, up to and including deadly force, when faced with the threat of imminent bodily harm or death. If we answer that way on the exam it will be correct." Now if something goes bump in the middle of the night and you find someone in your house that doesn't belong there you draw down on them and put them down. If you start analyzing whether you are faced with the threat of imminent bodily harm or death under the law you will be killed in your own home."
I was also advised by my father, a combat veteran and former cop, the best weapon for home defense is a 12 gauge shotgun. High powered pistol and rifle rounds can easily go through walls and strike friendlies. Additionally, in the moment, adrenaline, surprise, poor lighting and fast moving events favor a shotgun's spread versus the accuracy needed to aim a pistol or rifle.